Rapid Oxidation of Selenides,Selenoxides, Tellurides,and Telluroxides with Aqueous Sodium Hypochlorite

A simple and convenient procedure for the rapid oxidation of a variety of selenides, selenoxides, tellurides, and telluroxides with aqueous sodium hypochlorite to selenones and tellurones, respectively, has been reported in dimethylformamide at ambient temperature.     

Elastic waves in an electro-microelastic solid

The present study is concerned with the wave propagation in an electro-microelastic solid. The reflection phenomenon of plane elastic waves from a stress free plane boundary of an electro-microelastic solid half-space is studied. The condition and the range of frequency for the existence of elastic waves in an infinite electro-microelastic body are investigated. The constitutive relations and the field equations for an electro-microelastic solid are stemmed from the Eringen’s theory of microstretch elasticity with electromagnetic interactions. Amplitude ratios and energy ratios of various reflected waves are presented when an elastic wave is made incident obliquely at the stress free plane boundary of an electro-microelastic solid half-space. It has been verified that there is no dissipation of energy at the boundary surface during reflection. Numerical computations are performed for a specific model to calculate the phase speeds, amplitude ratios and energy ratios, and the results obtained are depicted graphically. The effect of elastic parameter corresponding to micro-stretch is noticed on reflection coefficients, in particular. Results of Parfitt and Eringen [Parfitt, V.R., Eringen, A.C., 1969. Reflection of plane waves from a flat boundary of a micropolar elastic half-space. J. Acoust. Soc. Am. 45, 1258–1272] have also been reduced as a special case from the present formulation.     

Studies on the curing kinetics of epoxy resins using silicon containing amide-amines

Curing kinetics of diglycidyl ether of bisphenol-A (DGEBA) in the presence of novel silicon containing amide-amines were investigated by the dynamic differential scanning calorimetry. Silicon containing amide-amines were prepared by reacting 2.5 moles of 4,4'-diaminodiphenyl ether (E)/4,4'-diaminodiphenyl methane (M)/3,3'-diaminodiphenyl sulfone (mS)/bis(m-aminophenyl) methyl phosphine oxide (B) with one mole of bis(4-chlorobenzoyl) dimethyl silane. The multiple heating rate method (5, 10, 15 and 20°C min^-1) was used to study the curing kinetics of epoxy resins in the presence of stoichiometric amounts of amide-amines having molecular masses in the range of 660 to 760 g mol^-1. The peak exotherm temperature depends on the heating rate as well as on the structure of amide-amines. Activation energy of curing reaction as determined in accordance to the Ozawa's method was found to be dependent on the structure of amine. The thermal stability of the isothermally cured resins was also evaluated using dynamic thermogravimetry in a nitrogen atmosphere. The char yield was the highest in case of resins cured with amide-amines having both phosphorus and silicon atoms. This revised version was published online in July 2006 with corrections to the Cover Date.     

ANALYSIS OF MULTIPLE PHOTORECEPTOR PIGMENTS FOR PHOTOTROPISM IN A MUTANT OF Arabidopsis thaliana

Abstract
The shape of the fluence-response relationship for the phototropic response of the JK224 strain of Arabidopsis thaliana depends on the fluence rate and wavelength of the actinic light. At low fluence rate (0.1 μmol m^-2s^-1), the response to 450-nm light is characterized by a single maximum at about 9 μmol m^-2. At higher fluence rate (0.4 μmol m^-2s^-1), the response shows two maxima, at 4.5 and 9 μmol m^-2. The response to 510-nm light shows a single maximum at 4.5 μmol m^-2. Unilateral preirradiation with high fluence rate (25 μmol m^-2s^-1) 510-nm light eliminates the maximum at 4.5 μmol m^-2 in the fluence response curve to a subsequent unilateral 450-nm irradiation, while the second maximum at 9 μmol m^-2 is unaffected. Based on these results, it is concluded that a single photoreceptor pigment has been altered in the JK224 strain of Arabidopsis thaliana.     

An efficient 1,3-allylic carbonyl transposition of chalcones

Abstract  A very simple, convenient, and efficient procedure is reported for the 1,3-allylic carbonyl transposition of chalcones. The transposition can be achieved by reduction of chalcones to 1,3-diarylpropan-1-ols and dehydration of the latter to give 1,3-diarylpropenes followed by benzylic/allylic oxidation. Graphical abstract        

A note on completeness and strongly clean rings

Many authors have investigated the behavior of strong cleanness under certain ring extensions. In this note, we investigate the classical problem of lifting idempotents, in order to consolidate and extend these results. Our main result is that if R$R$ is a ring which is complete with respect to an ideal I$I$ and if x$x$ is an element of R$R$ whose image in R/I$R/I$ is strongly π$\pi$-regular, then x$x$ is strongly clean in R$R$. This generalizes Theorem 2.1 of Chen and Zhou (2007)  [9].     

An ensemble of idempotent lifting hypotheses

Lifting idempotents modulo ideals is an important tool in studying the structure of rings. This paper lays out the consequences of lifting other properties modulo ideals, including lifting of von Neumann regular elements, lifting isomorphic idempotents, and lifting conjugate idempotents. Applications are given for IC rings, perspective rings, and Dedekind-finite rings, which improve multiple results in the literature. We give a new characterization of the class of exchange rings; they are rings where regular elements lift modulo all left ideals.We also uncover some hidden connections between these lifting properties. For instance, if regular elements lift modulo an ideal, then so do isomorphic idempotents. The converse is true when units lift. The logical relationships between these and several other important lifting properties are completely characterized. Along the way, multiple examples are developed that illustrate limitations to the theory.     

Positive vector measures with given marginals

Suppose E is an ordered locally convex space, X ₁ and X ₂ Hausdorff completely regular spaces and Q a uniformly bounded, convex and closed subset of M _t ⁺ (X ₁ × X ₂, E). For i = 1, 2, let μ _i   M _t ⁺ (X _i , E). Then, under some topological and order conditions on E, necessary and sufficient conditions are established for the existence of an element in Q, having marginals μ ₁ and μ ₂.     

Product of uniform measures

For i =  (1, 2), let X _i be Hausdorff uniform spaces and μ _i uniform measures on X _i . We determine the existence of the product uniform measure μ ₁⊗μ ₂ on X ₁  ×  X ₂ and prove a Fubini type theorem and a continuity property. The result is extended to vector-valued uniform measures.